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Hierarchy Level


Enable automatic Virtual Chassis port (VCP) conversion (also called VCP autoprovisioning) in a Virtual Chassis.

VCP links connect members in a Virtual Chassis using supported VCP ports on the member switches. Ports that are supported as VCPs and are not dedicated VCPs or configured as VCPs by default must be converted into VCPs to use them to interconnect Virtual Chassis members. You can manually convert a supported port into a VCP port using the request virtual-chassis vc-port command, or when automatic VCP conversion is enabled, a port will be automatically converted into a VCP under the following conditions:

  • LLDP is enabled on the interfaces for the members on both sides of the link. The two interfaces exchange LLDP packets to accomplish the port conversion.

  • The Virtual Chassis must be preprovisioned with the switches on both sides of the link already configured in the members list of the Virtual Chassis using the set virtual-chassis member command.

  • The ports on both ends of the link are supported as VCPs and are not already configured as VCPs.

You might want to invoke automatic VCP conversion when adding a new switch to an existing Virtual Chassis or adding a redundant VCP link between two existing members of a Virtual Chassis.


When automatic VCP conversion is enabled in a Virtual Chassis with switches that have dedicated VCPs (EX4200, EX4500, or EX4550 Virtual Chassis), if network or uplink ports are automatically converted into VCPs to create a redundant link with a dedicated VCP connection, you must reboot the Virtual Chassis to avoid creating a traffic loop within the Virtual Chassis. See Troubleshooting an EX Series Virtual Chassis for more information on this potential issue.

Required Privilege Level

system—To view this statement in the configuration.system-control—To add this statement to the configuration.

Release Information

Statement introduced in Junos OS Releases 14.1X53-D47 and 15.1R7.